
public class DuckCall implements IQuackable {

	Observable observable;
	
	public DuckCall()
	{
		observable = new Observable(this);		
	}
	
	public void quack()
	{
		System.out.println("Quack");
		notifyObservers();
	}
	
	public void registerObserver(IObserver observer)
	{
		observable.registerObserver(observer);
	}
	
	public void notifyObservers()
	{
		observable.notifyObservers();
	}
}